Coated foam scouring pad



Aug. 21, 1962 A. F. REILLY COATED FOAM SCOURING PAD Filed May 27, 1960 FIG. 2

INVENTOR.

ALBERT E REILLY ATTORNEY United States Patent 3,05%,414 COATED FOAM SCOG PAD Albert F. Reilly, Clarence, N .Y., assignor to General Mills, Ina, a corporation of Delaware Filed May 27, 1960, Ser. No. 32,319 6 Claims. (Cl. 117- 98) The present invention relates to improvements in scouring pads. More particularly, it pertains to scouring pads comprised of a flexible, resilient foam body with a frangible coating on a surface thereof.

Some scouring pads currently in use are, made from metallic W001 or inorganic abrasive grains. A disadvantage of such pads is that they tend to scratch metal or ceramic surfaces.

Accordingly, one object of this inventionis to provide a scouring pad which will not tend to scratch metal or ceramic surfaces.

A further object of this invention is to provide a scouring pad having an 'abrasivesurface which will not readily wear away. 7

Another object is to provide a scouring pad which will not become matted and from which food particles can be readily rinsed out after use.

Other objects and advantages in the invention will be apparent from the following description in which certain preferred embodiments of the invention are disclosed.

According to the present invention the desired objects can be accomplished by coating one surface of aflcxible, resilient foam body with a frangible organic coating. This frangible coating is sufficiently brittle so that bending of the foam body will tend to crack said coating in many places. These cracks form sharp cutting edges which provide scouring action but said cutting edges are composed of an organic material which is not abrasive 'so that the scouring pad willnot scratch metal or ceramic surfaces.

In the drawings which form part of this application, FIGURE 1 is a perspective view of a scouring pad made in accordance with the present invention; and

FIGURE 2 is a sectional view through the line 22 of FIGURE 1.

The scouring pad shown in FIGURE 1 includes a flex- .ible, resilient foam body 10 with a frangible organic rigid type bodies which can be bent or flexed'in such a Way that the coating 12 can be cracked or shattered in many places.

In the preferred embodiment the polyurethane foam bodylt), as is well known in the art, is derived-from approximately %,24, and

Zififihgili Fatented Aug. 21, 1952 ice Parts by Weight Fine Pore Coarse Pore Mixed Pore Polyester resin Q 100 100 Toluene liisocyanate mixture of 20%, 2, 40. 2 40 N-Methylmorpholiue. 1. 2 1. 2 1. 2 Witeo 77-86 2. 3 2. 3 2. 3 Tricresyl phosphat 3. 4 3. 4 3. 4 Water 3. 5 3. 5 3. 5 Anti static agent 4 Glycerol 1. 25

The frangible organic coating 12 can be provided by a number of products such as epoxy resins, phenolics, urethanes and acrylics. For the purposes of illustration, specific reference will be made herein to a frangible coating of a. cured epoxy'resin. However, any frangible coating of phenolic, urethane or acrylic resins may be used.

In the preferred embodiment the frangible organic coating 12 is an epoxy resin cured with a flexibilizing modifier. The preferred epoxy resins are the liquid epoxy resins which are the reaction products of bisphenol A and epichlorohydrin, a wide variety of which are available commercially. The preferred flexibilizing modifier is an amino imidazoline which is also available commercially and is the reaction product of an alkylene polyamine and polymeric fat acids. in general three parts of the epoxy resin are used with one part of the amino imidazoline.

Any epoxy resin which will provide a frangible organic coating may be used in this invention. Such epoxy materials are of awide variety. In general they contain a plurality of epoxy groups capable of reaction with a curing agent. The typical commercially available epoxy materials are complex reaction products of polyhydric phenols with polyfunctional halohydrins. A large number of this type of epoxy resins are disclosed in Greenlee Patents 2,585,115 and 2,589,245. 7

Typical polyhydric phenols useful in the preparation of epoxy resins include resorcinol, novolac'resins, and various bisphenols resulting from the condensaton of phenol with aldehyde and ketones such as formaldehyde, acetaldehyde, acetone, methyl ethyl ketone and the like. A typical epoxy resin is the reaction product of epichlorohydrin and 2,2-bis (p-hydroxy phenyl) propane (bisphenol A), the resin having the following theoretical structural formula,

where n' is O or an integer up to 10. Generally speaking n will be no greater than 2 or 3 and is preferably 1 or Those prepared from the novolac resins and epi- .lar'iweight of the resin divided by the mean number of equivalent Weight of 140 to 300, the'preferred epoxy 7 use of catalysts and/or reactive hardeners. These catcalledflexibilizing modifiers. ,Curing agents which may be employed in the present invention can be either nitroamide, amino-polyamide, amino-imidazoline, iminothat the above list of curing agentsare merely illustrative and should not be construed'as limiting the present invena p v j' in any That is, any cun'ng agent which will 50 and other similar materials; In the polymerization proc- A ess for the preparation of a polymeric fat acid the unsatu-V 7 rated fatty acids combine to provide a mixture of dibasic f and higher polymeric fat acids. These acids are often referred to as dimers, trimers and so forth. Inplace of a will adhere "to a flexible, resilient foam body can be used f parts by weight of epoxy resin with from five to Qther amino containing' compounds such as amino-amides, I amino-polyamides, and im'ino linked polyamide-pol'yimir 7 V dazolines having relatively high aminenumbers can also 1 111101.610 a Acwrdmgly, 11 Should beiappreclhydroxide equivalent to the amine groups in one gram of product, The amine number thereby indicates the or .acteristics of such compounds. ,In general the amino o compounds suitable for this invention have aminenumj 4 a V o The amino compounds are derivedby the reaction of a polyamine with either a fatty acid, polymeric fat acid, or

chlorohydrin have the structural formula,

* l t, .B. R |nR in which R is a hydrogen or an alkyl radical having from 1 to 4 carbon atoms and n is an integer from 1 to 8.

Epoxy resins may be characterized further by ref- 7 I erence to their epoxy equivalent Weight, the epoxy equivapreparing the am no containing compounds are the alkyllent weight of pure epoxy resins. being the mean molecu- 15 we polyamlnes such as ethylene diamm dlethyltme I amine, tetraethylene pentamine, di-l,3-propane tnamme,

sults in an amino compound having unreactedamino epoxy radicals per molecule, or in any case the number .ofgrams of epoxy resin equivalent to one epoxy group or one gram equivalent of epoxide. Whilecertain spe- 7 can be represented by the formula H N(RNH) HWh6I R is an alklene radical and'n isanj integer from 2 to 6;

cific epoxy which are the most readily available While the alkyleneradical is generally ethylene, alkylene commercially have been described, it is understood that radicals having p 6 ar o atoms are Suitable. Qthenep oxyrcsinous compositionsencornpassed by this invention are those liquid epoxy resins having an epoxy usualconditions employed for this purpose. Generally ams of compound per epoxy group.;,A number of com- 7 gr this involves reaction at about 200 for approximately 3 mercially available epoxy resins have the above characteri ti hours. The polyarnides' derived from diethylene triamine generally have a lower amine number in the range of 50 The normally liquid epoxy resins must be converted to I V A a solid end product order to provide the desired frangito 200. If longer chain polyanunes are employed the ble coating 12 for the foam body 10. This is called curamlne mllflbef' W 111 PP 1Y hl r ing and can be accomplished in known manner by-the The ammomndazolmes whlch e p y 111 this malysts and/or reactive hardeners'are usually referred to Y P Y d fid o fo t e imidazoline in g m -C ji typ of curing agents are ring. The'reactron 1s carried out under the usual con- 7 gen containing or acid type curing agents. Specific exjamples of nitrogen containing curing agents; that may be .7 employedwith the present invention are amino-mono- 49 3115 l linked polyamide polyirn idazoline, aliphatic and'aromatic amides and polyamides. V

Specific examples of acid type curing agents that may semldl'ymg 0 Of The ffi aclds I 1116 811111116 hp be employed with the present invention are polybasic acids 1211601101 asters ofothese aclds, a P rtesomces rich and anhydrides such as phthalic, chlor'endic, pyromellitic or dodecenyl succinic anhydride. It should be understood 7 V v u sunflower, safiiower and dehydrated castor oil. Suitable fatty acids may also be obtained from tall oil, soap stock convert the liquid epoxy resin to a frangible coating that in carrying out the present'invention.

In general the curing agents mentionedabove' are comp g W *bined in the following proportions: one hundred (100) 556115 'E fi of p1ymenZat1Qn n method of polymerization may be employed whether the resultant (v30) partsby weight of cming agent In addi polymer possesses residual unsaturation or not. The tion, one could use combinations'of said curing 'ag ents asris n know in he 1 nclude the polymerized mixture of acids which usually firh f fi pun-Hg e fdr mr fi i contain a predominant portion of dimer acids, a small tionwhich is a flexibilizing modifier is an amino-con- ,taining compound known as an amino-infidazoline. some resldualv q At the present time the most readily available naturally ated that polymeric 'fat acids will as a practical matter result from fatty acid mixtures that contain a preponder-ance of linoleic acid. It should also be appreciated that since linoleic acid occurs in nature as agcomaml-ne groups available for reaction and serveshs. an plex mixture in every instance it is available in various dication of the structure and usefulness of the compound. The amine number is therefore one of the chief charbe used to cure the epoxy resin. The amine number referred to herein is the number of milligrams of potassium linoleic acid that has been laboriously purified to crude sources such as tall oil and soap stock which contains "substances otherthan fatty acids. One method of obbers in'the range of 50 to 700.

an epoxidized fatty acid or the esters thereof which re groups. The polyamines which may be employed in di-l,2-propane triamine, and the like. The polyamines The amino-polyamides which may be employed in this invention are those derived by reacting an excess of the f previously mentioned polyamines with polymeric fat acid. equivalent Weight being lSS to 220, expressed in terms of 25 The i i i r i n m y arri d out n rt e vention are prepared in an analogous] manner. TheQI ditions employed: for imidagoline formation which gen- 7 I erally involves heating to about 280 to 315 C. for ap proximately 2 to 3 hours. Any amino-polyamide formation willgenerally be converted to imida zoline form at I The polymeric fat acids which: may be employed preparing the amino-polyamides and amino imidazolines' are those resulting from the polymerization of drying or in linoleicacid. Suitable drying orv semidrying oils in clude soybean, linseed, tung, perilla, cottonseed, corn,v

term polymericfat acid-as used herei n is intended to' quantity of triiner and higher polymeric fat acids and o occurring polyunsaturated acidavailable in large quandegrees of purity ranging from relatively expensive pure taining the linoleic rich fatty acids is by separating'a major portion of the oleic and saturated fatty acids from any convenient and economical source of fatty acids having a high iodine value. In addition dimeric and polymeric fat acids can be prepared from fatty acid compositions rich in oleic acid by a catalyzed polymerization. Such dimeric and polymeric fat acids may be used in this invention. Furthermore, polymeric fat acids are readily available commercial products.

The amino-monoamides which may be employed in this invention are the products of the reaction of the previously mentioned alkylene polyamines and fatty acids having from 8 to 22 carbon atoms. The amidification reaction may be carried out under the usual conditions employed for this purpose, which involves reaction at about 170 C. for approximately 2 hours. In general the same acids which are used to prepare the polymeric fat acids are suitable. Suitable fatty acids are also obtained from tall oil. In addition such fatty acids are readily available commercial products. One such product is the tall oil fatty acids sold by Hercules Powder Company under the name of Pamak.

If the epoxidized fatty acids or their alkyl esters are employed complex amino-containing imino-linked-polyamide-polyimidazolines result. The alkyl esters which can be used in preparing the complex product used in this invention are generally those having an alkyl group having from 1 to 6 carbon atoms. The reaction with the polyamine may be carried out in several ways. One preferred method is to carry out the reaction at about 150 C., at which temperature both imidazoline and amide linkages result. Another method is to carry out the reaction at about 100 C., in which case the formation of amide linkages are favored, or at 200 C., and above at which temperatures imidazoline linkages are favored. In general, temperatures in excess of 300 C., should be avoided as deleterious side effects may result. The product will have an amine number in the range of from 50 to 700.

The epoxy fatty acid compounds, i.e., fatty acid esters and fatty acids employed may be prepared in any of the known methods. One method is to react any of the various unsaturated fatty acids mentioned previously or their esters with peracetic acid at about room temperature. The peracetic acid may be preformed before the epoxidation step or formed in situ by any one of the well known processes involving sulfonic acid resins utilizing hydrogen peroxide and acetic acid. Epoxidation can also be performed by the use of formic acid and hydrogen peroxide. The epoxides can also be prepared by addition of hypochlorous acid to the carbon-carbon double bond followed by dehydrochlorination.

In carrying out the present invention an epoxy resin of bisphenol A and epichlorohydrin having an epoxy equivalent weight of about 200 and an amino imidazoline of the polymeric fat acids and triethylene tetramine having an amine number of about 375 are mixed in a 3:1 ratio at room temperature. This mixture has a pot life of approximately 60 minutes. This mixture has a viscosity of 15,000 centipoises :2500 centipoises and is roll coated, as is well known in coating art, onto a surface of the foam body 10. In the preferred embodiment the 3:1 mixture is applied in amounts of .05 to 1 gram per square inch. The mixture can be applied in amounts of .01 to 2 grams per square inch. The preferred mixture gels in about two hours at room temperature. At this point, the cure is not complete, but the material can be handled. The cure continues and under normal conditions it is complete at the end of four days. If elevated temperatures are used the cure time can be shortened as shown below:

Temperature F.): Cure Time (Min.)

In view of the principles set forth herein, I have shown some of the ways of carrying out the present invention and some of the equivalents which are suggested by these disclosures.

What is claimed is:

1. A scouring pad comprising a flexible, resilient foam body having a frangible organic coating covering at least a portion of one surface thereof.

2. A scouring pad as set forth in claim 1 in which said frangible coating is selected from the group consisting of an epoxy, a phenolic, a urethane, and an acrylic resin coating.

3. A scouring pad as set forth in claim 1 in which said frangible coating comprises a cured epoxy resin.

4. A scouring pad set forth in claim 3 in which said frangible coating is cured with a nitrogen-containing curing agent.

5. A scouring pad as set forth in claim 1 in which said frangible coating comprises a fluid epoxy resin cured with an amino compound selected from the group consisting of amino-amides, amino-polyamides, amino-imidazolines, and imino-linked polyamide-polyimidazolines.

6. A scouring pad comprising a flexible, resilient polyurethane foam body having a frangible organic coating secured to at least a portion of one surface thereof, said coating being a mixture of three parts by weight of epoxy resin and one part by weight of an aminoimidazoline.

References Cited in the file of this patent UNITED STATES PATENTS UNITED STATES PATENT OFFICE CE "HFCATE 0F CORRECTION Patent No.,. 3,95OA14L August 21 1962 Albert F, Reilly It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 43, for "amides and polyamides" read amines and polyamines column 4, line l9 for "alklene" read alkylene Signed and sealed this 1st day of January 1963.

(SEAL) Aitestz' v ERNEST w. SWIDER DAVID LADD Attesting Officer Commissioner of Patents 

1. A SCOURING PAD COMPRISING A FLEXIBLE, RESILIENT FOAM BODY HAVING A FRANGIBLE ORGANIC COATING COVERING AT LEAST A PORTION OF ONE SURFACE THEREOF. 